There has been conventionally proposed a monitoring movable body (e.g. JP2005-275723A) equipped with a foreign matter sensing sensor which senses an obstacle on a road surface, and the like and capable of detecting position information of a foreign matter in order to manage road safety. Specifically, the monitoring movable body includes a positioning device which outputs travelling position information of a movable body, a foreign matter sensing sensor which monitors a foreign matter on a road surface to obtain foreign matter sensing information, and a foreign matter position computing device which detects foreign matter position information from the travelling position information and the foreign matter sensing information.
In JP2005-275723A, a foreign matter on a runway surface is detected by a foreign matter sensing sensor. By contrast, a construction machine may approach various structures by slewing or travelling or a worker may work in proximity to the construction machine. In such a case, if it is possible to sense various structures or a worker approaching closer and check approach information by those concerned such as a site supervisor and the like, a condition at that time can be confirmed with an operator based on the information, or the like to serve for safety of subsequent work.